The invention relates to keyboard switches and is directed more particularly to a low-profile keyboard switch having an improved guide structure.
Prior to the present invention pushbutton keyboard switches have included keys having central plungers which were guided along relatively long tubular channels or guides formed in the cover surface of the keyboard switch housing, as is disclosed, for example, in German Patent No. 33 02 793. The lengths of these plungers and guides have been thought to be necessary in order to prevent the actuating force of the key from increasing noticeably when the key is pressed at a point away from its center. Such an increase in force results from the tilting of the plunger in its guide.
According to prevailing ergonomic standards for alphanumeric keyboards, e.g., video work stations, the average overall height of the keyboard must not exceed 30 mm. Because of the just described tilting problem, it has not been possible to meet these standards with keyboard switches of the above mentioned type.